UMP: Initial plumbing

runtime/parachains/src/inclusion.rs

@@ -155,6 +155,8 @@ decl_error! {
 		InternalError,
 		/// The downward message queue is not processed correctly.
 		IncorrectDownwardMessageHandling,
+		/// At least one upward message sent does not pass the acceptance criteria.
+		InvalidUpwardMessages,
 	}
 }
 
@@ -412,6 +414,7 @@ impl<T: Trait> Module<T> {
 					&candidate.candidate.commitments.head_data,
 					&candidate.candidate.commitments.new_validation_code,
 					candidate.candidate.commitments.processed_downward_messages,
+					&candidate.candidate.commitments.upward_messages,
 				)?;
 
 				for (i, assignment) in scheduled[skip..].iter().enumerate() {
@@ -544,6 +547,7 @@ impl<T: Trait> Module<T> {
 			&validation_outputs.head_data,
 			&validation_outputs.new_validation_code,
 			validation_outputs.processed_downward_messages,
+			&validation_outputs.upward_messages,
 		)
 	}
 
@@ -570,6 +574,10 @@ impl<T: Trait> Module<T> {
 			receipt.descriptor.para_id,
 			commitments.processed_downward_messages,
 		);
+		weight += <router::Module<T>>::enact_upward_messages(
+			receipt.descriptor.para_id,
+			commitments.upward_messages,
+		);
 
 		Self::deposit_event(
 			Event::<T>::CandidateIncluded(plain, commitments.head_data.clone())
@@ -693,6 +701,7 @@ impl<T: Trait> CandidateCheckContext<T> {
 		head_data: &HeadData,
 		new_validation_code: &Option<primitives::v1::ValidationCode>,
 		processed_downward_messages: u32,
+		upward_messages: &[primitives::v1::UpwardMessage],
 	) -> Result<(), DispatchError> {
 		ensure!(
 			head_data.0.len() <= self.config.max_head_data_size as _,
@@ -722,6 +731,14 @@ impl<T: Trait> CandidateCheckContext<T> {
 			),
 			Error::<T>::IncorrectDownwardMessageHandling,
 		);
+		ensure!(
+			<router::Module<T>>::check_upward_messages(
+				&self.config,
+				para_id,
+				upward_messages,
+			),
+			Error::<T>::InvalidUpwardMessages,
+		);
 
 		Ok(())
 	}

runtime/parachains/src/inclusion_inherent.rs

@@ -35,6 +35,7 @@ use frame_system::ensure_none;
 use crate::{
 	inclusion,
 	scheduler::{self, FreedReason},
+	router,
 };
 use inherents::{InherentIdentifier, InherentData, MakeFatalError, ProvideInherent};
 
@@ -115,6 +116,9 @@ decl_module! {
 			// Note which of the scheduled cores were actually occupied by a backed candidate.
 			<scheduler::Module<T>>::occupied(&occupied);
 
+			// Give some time slice to dispatch pending upward messages.
+			<router::Module<T>>::process_pending_upward_messages();
+
 			// And track that we've finished processing the inherent for this block.
 			Included::set(Some(()));
 

runtime/parachains/src/router.rs

@@ -29,6 +29,7 @@ use frame_support::{decl_error, decl_module, decl_storage, weights::Weight};
 use primitives::v1::{Id as ParaId, InboundDownwardMessage, Hash};
 
 mod dmp;
+mod ump;
 
 pub use dmp::QueueDownwardMessageError;
 

runtime/parachains/src/router/ump.rs

@@ -0,0 +1,59 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use super::{Trait, Module};
+use crate::configuration::HostConfiguration;
+use sp_std::prelude::*;
+use frame_support::weights::Weight;
+use primitives::v1::{Id as ParaId, UpwardMessage};
+
+impl<T: Trait> Module<T> {
+	/// Check that all the upward messages sent by a candidate pass the acceptance criteria. Returns
+	/// false, if any of the messages doesn't pass.
+	pub(crate) fn check_upward_messages(
+		config: &HostConfiguration<T::BlockNumber>,
+		para: ParaId,
+		upward_messages: &[UpwardMessage],
+	) -> bool {
+		drop(para);
+
+		if upward_messages.len() as u32 > config.max_upward_message_num_per_candidate {
+			return false;
+		}
+
+		for _ in upward_messages {
+			return false;
+		}
+
+		true
+	}
+
+	/// Enacts all the upward messages sent by a candidate.
+	pub(crate) fn enact_upward_messages(para: ParaId, upward_messages: Vec<UpwardMessage>) -> Weight {
+		drop(para);
+
+		for _ in upward_messages {
+			todo!()
+		}
+
+		0
+	}
+
+	/// Devote some time into dispatching pending upward messages.
+	pub(crate) fn process_pending_upward_messages() {
+		// no-op for now, will be filled in the following commits
+	}
+}